Secondary circuit connection



p 1941- E. A. MALLETT 2,254,436

SECONDARY CIRCUIT CONNECTION Filed July 18, 1940 3nventor (Ittorneg Patented Sept. 2,

UNITEDVT:

sTArEs PATENT oFFlce I SECONDARY CIRCUIT CONNECTION Edwin A. Mallett, Warren, Ohio, asslgnor to Taylor-Winfield"Corporation, Warren, Ohio, a

W corporation of Ohio Claims.

This invention relates to an electric welding machine and more particularly to an improved flexible connection between the transformerlsec ondary and the movable electrode' it'has been common practice to utilize'a plurality of flat flexible bands connected at one 'erid'with the transformer secondary terminal and at their other ends with a block rigidly attached to thg movable electrode holder. Freedom of movement of the holder is aided by looping the" -flexible=bands about an axis extending perpendicular to the direction of movement of the movable electrode.

As a result of the above described construction there is a lateral force applie'dtotheslide supporting the movable electrode'of the machine due to the inherent spring force exerted by the bands and also due to the force exerted inthe same direction by the heavy flow of current through the bands, which flow tends to straighten out the looped bands. This increases substantially the friction between the guide members and the electrode supporting slide and mitigates against the most desirable operating characteristic of the machine. It is, of cours' desirable that the movable electrode be free ,to move especially upon the softening of the metal to effect a quick forging movement without undue upsetting of the metal. This is difficult to accomplish when the electrode carrier tends to stick and upon release jumps forward with a surging motion.

The primary object of the invention is to overcome the above mentioned objectionable operating characteristics of the apparatus ofthe present construction and this is accomplished in accordance with the invention by utilizing two looped sets of conductor bands extending from the transformer terminal to the electrode holder in opposed relationin such manner that the outward forces exerted by the looped bands by reason of their inherent resiliency and the flow of current therethrough are equal and opposite with the result that no lateral force from the flexible connecting bands is exerted on the guides for the movable electrode slide.

Another object of the invention is the provision of an improved construction for a welding machine incorporating the features and having the operating characteristics pointed out above.

These and other objects and advantages of the invention will become apparent from a consideration of the following detailed specification and the accompanying drawing wherein there is spel: implication July 18, 1940, Serial No. 346,167

ciflcally disclosed a preferred embodiment of the invention.

In the drawing: Figure 1 is a side view of a portion of a welding machine utilizing the principles of the present invention; and

Figure 2 is a front view partly in section of the apparatus of Figure 1, the view being taken along the line IIII of Figure l.'

In the drawing, reference numeral ll indicates generally the main frame of the weldingmachine which in accordance with usual practice encloses and supports the welding transformer, which transformer may have a pair of fixed secondary terminals II and i2. The normally flxed electrode l3 of the machine is supported in a holder [4 which in turn is supported on a bracket i5 adjustably secured to the front face of the frame Ill. Welding current may be conducted to the holder l4 by a rigid bar i6 which is connected with the secondary terminal II.

As stated above suitable means may be provided to slidably support the movable electrode of the machine and in accordance with the apparatus specifically illustrated this may consist of a cylindrical member 20 carried at the outer end of a bracket 2| extending outwardly from the front face of the frame or housing ill and a quill 22 slidably received in the bore of the guide 20. Quill 22 is adapted to be moved vertically by suitable fluid pressure or mechanical means (not shown) and carries at its lower end a chuck 23 adapted to partially receive an electrode holder 24. Carried by the outer end of the holder 24 is the normallymovable electrode 25 and positioned below the holder 24 and provided with a recess to receive a portion of the holder is a connecting bar 26 which is suitably clamped to the chuck 23 and holder 24 by any suitable means (not shown).

The inner end of the bar 26 extends upwardly and inwardly, as shown in Figure 1 of the drawing, and has its inner end bifurcated at 21, as shown in Figure 2 of the drawing. Transformer secondary I2 is of substantial width-consider.-

ably wider than the width of the bifurcations 21 and extending forwardly from each side edge of the terminal I2 is a lug 28. Extending from each of the lugs 28 to one of the bifurcations 21 is a conductor 30 which, as shown, is looped downwardly to provide suflicient flexibility and length of material to enable the bifurcations 21 to be moved vertically relative to the lugs 28. One end of each of the conductors 30 is securely fastened to one of the lugs 28 of the fixed secondary terminal l2 and the other end is rigidly connected with one of the bifurcations 21. Conductors 30 are, in accordance with usual practice, built up of a plurality of thin flexible bands of highly conductive matezontal direction by either one or the looped conductors, by reason of the inherent resiliency in the looped conductors or by the flow of heavy welding current therethrough, will be opposed in equal measure by a similar force exerted by the other or the looped conductors. Thus, no horizontally disposed force will be transmitted through the member 28 to the quill or slide 22 during operation of the machine and consequently friction between the slide and its guide 20 will be kept to a minimum. The tendency of the quill or slide to cant and stick in its guide is materially reduced and the machine may be operated with better results. By positioning the flexible conductors 30 on the diametrically opposite side of the axis of the quill 22 from the electrode 25 the forces reacting against vertically downward movement of the quill 22 during operation of the machine are balanced to a certain extent since the movement in one direction, caused by the force exerted on the tip oi. electrode 25, is offset to a certain extent by the movement in the opposite direction exerted by the conductors 30 acting through the longer arm from the conductors to the axis of the quill.

The above specifically described embodiment of the invention should be considered as illustrative only as many changes may be made therein without departing from the spirit or .scope of the invention. For example, other means than the bifurcated bars 28 may .be employed to con duct welding current from the flexible conductors to the movable welding electrode and various changes may be made in the arrangement of the two looped flexible conductors. The inner adjacent ends of the conductors may be clamped together and attached rigidly to the movable electrode holder or these ends may be connected with the fixed secondary terminal of the transformer and the divergent ends connected with the electrode holder. The slide 22 may assume a wide variety of different forms and the electrode holder may either be rigidly connected therewith or, as indicated in the drawing, the connection may be made through an air lock as fully disclosed in the co-pending application of Stanley M. Humphrey, Serial Number 306,127, filed November 25, 1939. Reference should therefore be had to the appended claims in determining the scope or the invention.

What I claim is:

1. In an electric welding machine the combination with a welding transformer having a pair of fixed secondary terminals, a normally fixed electrode, and a movable electrode, of means to convey welding current from one of said fixed terminals to the movable electrode comprising a pair of spaced parallel lugs rigidly connected with the said one of said terminals, a member electrically connected with said movable electrode and having a portion extending between but below said lugs, and a flexible conductor comprising laminations of flexible bands connected to each of said lugs and looped downwardly and inwardly towards said extended portion of said member, and means to connect the inner adjacent ends of each oi said conductors with said extended portion of said member.

2. In an electric welding machine the combination with a welding transformer having a pair or fixed secondary terminals, a normally fixed electrode, a movable electrode, a slide supporting said movable electrode, and a guide for said slide, 01' means to convey welding current from one 0! said fixed terminals to the movable electrode comprising a pair of spaced parallel lugs rigidly connected with the said one oi.- said terminals, a member electrically connected with said movable electrode and having a portion extending between but below said lugs, and a flexible conductor comprising laminations or flexible bands connected to each of said lugs and looped downwardly and inwardly towards said extended portion of said member, and means to connect the inner adjacent ends of each of said conductors with said extended portion of said member.

3. In an electric welding machine the combination with a welding transformer having a pair or fixed secondary terminals, a normally fixed electrode, a movable electrode, a slide supporting said movable electrode, and a guide for said slide. oi. means to conduct welding current to said movable electrode comprising a pair of flexible conductors each consisting of laminations of flexible bands, said conductors being looped inwardly towards each other, a conducting member connected with said movable electrode, means to secure the inner adjacent ends of said flexible conductors to said member, and means to secure the outer ends of said flexible conductors to one of the fixed secondary terminals of said transformer.

4. In an electric welding machin the combination with a welding transformer, a normally fixed electrode connected with one of the terminals of the transformer secondary, a movable electrode, a slide supporting said movable electrode, and a. guide for said slide, of means to conduct welding current from the other of the terminals of said transformer secondary to said movable electrode comprising a pair of flexible conductors each consisting of laminations of flexible bands, a conducting member connected with said movable electrode, the said other of said transformer secondary terminals comprising a conducting member, said flexible conductors being looped inwardly toward each other, means to secure the inner adjacent ends of said flexible conductors to one of said members, and means to secure the outer ends of said flexible conductors to the other of said members.

5. In an electric welding machine the combination with a welding transformer, a normally fixed electrode connected with one of the terminals of the transformer secondary, a movable electrode, a slide supporting said movable electrode, and a guide for said slide, of means to conduct welding current to said movable electrode comprising a pair or flexible conductors looped inwardly towards each other, a conducting member connected with said movable electrode, a second conducting member constituting the other terminal of said transformer secondary, means to secure the inner adjacent ends of said flexible conductors to one of said members, and means to secure the other ends of said flexible conductors to the other of said members, the arrangement of the parts being such that substantially no lateral force is exerted on said slide by said conductors.

EDWIN A, MALLETI. 

